Molecular genetic characterization of Amaranthus cruentus L. mutant lines derived from local and preferred Amaranthus cultivar

Abstract

Objective: Benin’s most appreciated Amaranthus cruentus L. «local» cultivar is susceptible to saline stress. Molecular diversity and relationships among nineteen gamma-irradiated A. cruentus mutant lines and their relative, the «local» cultivar, were studied to identify the best representative sample of those created mutant lines for further saline tolerance breeding.

Methodology and Results: The study was carried out by using a random amplified polymorphic DNA (RAPD) marker. Four RAPD (decamer) arbitrary primers (OPA-02, OPA-08, OPB-05 and OPB-08) out of eleven were able to discriminate all the genotypes sufficiently. Twenty amplicons, all polymorphic, were produced ranging from ~15O bp to ~1200 bp. The mean value of Shannon’s information index calculated for genetic diversity estimation was 0.43, and it ranged from 0.27 to 0.62. The genetic similarity coefficient ranged from 0.00 to 1.00. The sets of mutant lines L3 and L6; L12 and L8; L17 and L20; L13, L17 and L20; L17 and L20 appeared to be genetically similar, clustering together inside at 100 % similarity coefficient.

Conclusion and application of findings: Six distinct genotypes (L2, L6, L13, L16, L18 and L23) were identified as representative of the nineteen studied A. cruentus created mutant lines. This finding provides a diversity of materials to be considered for saline or other breeding objective. The current study is one step in a whole process of more productive and saline tolerant A. cruentus varieties’ creation. Mutation and molecular tools used in the current study cleared the way to an effective selection of good source of genes for A. cruentus breeding. The next step will be the saline test on the selected mutant lines to identify the most tolerant genotypes that can thrive despite saline effects and fit farmers’ and consumers’ needs.